You are observing in a Physical Therapy clinic and a patient presents with back pain. The images suggest that theyhave a disc herniation at the disk between L3 and L4. The PT you are working with believes that the disk is puttingpressure on the spinal nerve that contains the afferent and efferent neurons that control the patellar tendon reflex.Using the appropriate anatomy and physiology, describe the afferent and efferent portions of this stretch reflexpathway, including a description of the receptor and what it responds to. If you performed a patellar tendon reflex,describe whether you would expect to see an enhanced or diminished response and explain why.

A ‘reflex arc' is the path that nerve impulses follow to trigger a reaction. Because this process occurs so quickly, the reaction occurs before the message reaches the brain. As the brain's cognitive process is somewhat time-intensive, this results in a faster time-to-response.Answer: The patellar stretch reflex, also known as the knee-jerk reflex, is a stretch reflex that tests the "L2, L3, and L4 portions of the spinal cord." Stretching of the quadriceps femoris muscles results from hitting the patellar tendon. The sensory neurons inside the fibers produce action potentials as they are stimulated. The pseudounipolar sensory neurons carry those action potentials into the dorsal grey matter of the spinal cord, in which the sensory neuron axons synapse with the dendrites and cell bodies of the alpha motor neurons. Action potentials generated in motor neurons are transmitted from the ventral root to the stretched muscle, generating ACh release and triggering quadriceps femoris contraction. The muscle spindles stop firing when the muscle is stretched and the reflex is over.Conclusion: The knee of the affected limb extends quickly in response to patellar stretching. The patellar reflux is caused by the quadriceps femoris rapidly contracting in response to tapping on a stretched patellar ligament. As a result, the knee extends quickly. The reflex assesses the function of the spinal cord's L4 segment and the accompanying nerve roots.